AssignVariable across path chained proxies

Google Cloud Apigee
1

Hi,

I’m trying to define a variable in one proxy and expecting to access it in another proxy. The proxies are connected using LocalTargetConnection. I’m seeing a few issues on this:

  1. It seems that the variable set a the calling proxy is not visible in the called proxy. Is this the expected behaviour?

  2. The trace functionality doesn’t seem to work when invoking the parent proxy.

  3. The parent proxy is kind of filter proxy that passes through requests on /v2/* to the actual proxies in /

e.g. I have these proxies /cars, /movies, etc. then I want to create /v2/cars, /v2/movies, etc. that internally connect to the nonversioned proxies.

  1. I’d also like to override the HTTPTargetConnection/Path by assigning a dynamic path to the target.url variable, but apparently it still doesn’t work.

Please your help will be very appreciated.

2

Hello @Julio Rincon,

Please find the response.

  1. It seems that the variable set a the calling proxy is not visible in the called proxy. Is this the expected behaviour?

[Answer]: Yes. It is an expected behaviour, as the scope of the variables starts and ends within the proxy. So, to set the values of a variable in one proxy and fetch it from another, we typically, store the data in the KVM/Cache and Read the KVM/Cache from the other proxy. There are built in out of the box apigee policies available to read and/or the data from KVM/Cache. Details can be found here and here

  1. The trace functionality doesn’t seem to work when invoking the parent proxy.

[Answer]: Trace functionality is associated with a particular proxy. So, if you are tracing proxy “Parent”, you should see the run time details for this proxy only and not the “child” one and vice-versa

  1. The parent proxy is kind of filter proxy that passes through requests on /v2/* to the actual proxies in /

e.g. I have these proxies /cars, /movies, etc. then I want to create /v2/cars, /v2/movies, etc. that internally connect to the nonversioned proxies.

[Answer]: Its possible to call a proxy from another one. You can use the Target Endpoint properties to do so. That is you need to set the Target Endpoint the proxy path you wanted to hit.

  1. I’d also like to override the HTTPTargetConnection/Path by assigning a dynamic path to the target.url variable, but apparently it still doesn’t work.

[Answer]: You can do so by setting the path variable like this.Here the {uriPath} is a run time variable that I am setting to any value of my need. So the final request to the target endpoint would be {http://{IP}+{uriPath}}

    <HTTPTargetConnection>
       <LoadBalancer>
            <Server name="ABCD">
                <IsEnabled>true</IsEnabled>
            </Server>
        </LoadBalancer>
        <Path>{uriPath}</Path>
        <Properties/>
    </HTTPTargetConnection>
</TargetEndpoint>

Hope this helps..!

3

So can we dynamically choose between proxy chaining or httptarget connection? as in my scenario based on the request payload i need to either make a call to local proxy which in turn calls a target

or the payload has to be routed to an http target.

can we achieve this? @Meghdeep Basu